Investigation and Characterization of Cardiotech in animals (dogs) for potential as a cardiac imaging agent. Blood sampling and imaging was performed to characterize how the compound distributes. Information was also obtained via blood sampling about its plasma half life and extraction by the myocardium. Imaging showed that some activity was seen quickly in the heart, but even more activity was seen in the liver. This produced some interference with interpretation of myocardial uptake in the inferior wall. Work was done that showed the compound was fat-soluble to account for the liver uptake. Although a technetium labelled blood perfusion agent would be more ideal than current imaging, this agent has not shown the promise because of liver uptake.